Petrified wood is a material formed from trees that grew in past geological eras. Such "rarities" can tell a lot. Given the age of the trees, they can be used to trace the evolution of woody crops of a certain species, to learn about the time of their growth and the climate of past centuries.
How does the process of petrification of trees
Under natural conditions, wood residues decay, they are processed by microorganisms. This happens in the case of free access of air. But in some cases, a dead tree is not completely destroyed. This happens when it is buried under sediments (volcanic ash, landslides, landslides, glacial moraine, etc.), which impede the flow of oxygen. As a result, wood does not deteriorate, but fossilizes over time due to the replacement of organic substances with minerals. The physical properties of wood are completely changing, and it turns into a very dense and durable material.
In most cases, the organic tissue of the tree is replaced by silica minerals (silicified wood). This is mainly opal, chalcedony or quartz. Such fossils preserve the anatomical structure of wood. Less commonly, you can find the so-called marbled tree, the main substitute minerals in which are dolomite, calcite or siderite. In addition, gypsum, barite, jet, etc. can be substitute elements. More than 60 minerals are known to take part in the formation of wood fossils.
Basic properties of petrified wood
The mineral is characterized by a glass or wax shine, a conchoid fracture, and lack of cleavage. The hardness of petrified wood, depending on the substitute minerals, ranges from 4 to 6 on the Mohs scale. On one saw you can find areas that are significantly different in structure and color.
Due to impurities present in sediments or in water, petrified material can have a wide variety of colors. So, carbon gives the wood a black color; iron oxide - red, yellow or brown; copper, chrome and cobalt - green or blue; manganese - orange or pink; Manganese oxide - black or yellow.
Among the petrified trees you can find both coniferous and deciduous species. Coniferous petrification includes inclusions of amber.
Texture varieties
Petrified wood can have a different texture. The reason for this is many factors. Let us consider in more detail the existing texture varieties of petrified wood, and also due to what they were formed.
Homogeneous fossils
Varieties are included, which are characterized by an almost uniform structure with different colors. The stone has a clearly defined zonality, which is explained not by the difference between the color of the annual rings, but only by the presence of lines that limit them. The most famous representative of this group of fossils is the so-called opal tree, which is very light in color (can be almost white) and usually retains its primary structure.
Petrified Wood: Lens Texture
This texture develops in the process of filling large cells and pores of wood with chalcedony, opal, as well as iron hydroxides. Lenses are characterized by linear orientation. In some cases, it is emphasized by iron hydroxides developing in the same directions.
Spotted tree
It is the most common type of petrified tree. It is characterized by an opal-chalcedony composition with a significant admixture of iron hydroxides. The ratio of these three components is variable, which explains the uneven spotty color and texture of the mineral. Sometimes spotting is caused by relics of a tree that replaces chalcedony, preserving the outlines of cells against the background of an opal mass. This stone is inherent in color, including various shades of brown.
Concentric Zone Petrified Tree
The material is characterized by the alternation of opal or opal-chalcedony concentric strips having different colors. At the same time, they emphasize the pattern of tree growth rings in a cross section. The longitudinal section has a linear-banded texture, which is quite pronounced.
Lebid Petrification
This petrified tree has a carbon-opal or carbon-carbonate composition. The lines of tree rings are distinct and form a concentric (sometimes wavy-concentric) pattern. By decorative qualities, black petrified wood is compared with black jade or jet.
Where tree fossils are found
Most often, petrified trees are found in areas where volcanic eruptions occurred. The most famous place to discover this unique material is the so-called "Petrified Forest", located in Arizona and one of the US national parks (since 1962). The length of the petrified trunks reaches 65 m, the diameter is 3 m.
There are also a number of other petrified wood deposits that are located in different parts of the world. The most famous and significant fossilized forests are in Argentina, Brazil, Belgium, Greece, Canada, India, New Zealand, Russia, Ukraine, the Czech Republic, Georgia, Armenia and others. Many territories are national parks or natural monuments.
Petrified Wood Applications
Petrified wood - a stone, from ancient times used as a raw material for the manufacture of jewelry. Demand for them remains at a high level at the present time. This decorative stone lends itself very well to processing. It is perfectly cut, ground and polished, resulting in a kind of glass shine. When processing does not lose its wood texture.
Varieties of petrified wood with a small contrasting pattern are used to make inserts and medium-sized jewelry, such as beads, bracelets, etc. A decorative stone with distinct lines of tree rings is especially valuable. In the manufacture of jewelry, such samples are often combined with precious metals, other stones and glass.
Petrified wood is also used in the manufacture of various souvenir products and interior decoration items. It can be handles, ashtrays, vases, caskets, shelves, countertops and much more. For the manufacture of such products, material is often used, characterized by less pronounced zonality and having a spotted-banded or large-spotted pattern. The stone is highly regarded by collectors, given that trees are estimated to be millions of years old.
It should be noted that the petrified tree is considered a material with special healing properties. It helps people cope with stress and fight stress, increases the vitality of the body, protects against infectious diseases and injuries. According to folk medicine, a die made of petrified wood can relieve pain. To do this, just attach it to the sore spot. In Mongolian medicine since ancient times, with arthritis and similar diseases, a petrified tree (in the form of tablets) from the Gobi desert is applied to the joints.